The present invention relates to non-invasive functional assessment of coronary artery stenosis, and more particularly, to non-invasive functional assessment of coronary artery stenosis from medical image data and blood flow simulations.
Cardiovascular disease (CVD) is the leading cause of deaths worldwide. Among various CVDs, coronary artery disease (CAD) accounts for nearly fifty percent of those deaths. Despite significant improvements in medical imaging and other diagnostic modalities, the increase in premature morbidity and mortality for CAD patients is still very high. The current clinical practice for diagnosis and management of coronary stenosis involves the assessment of the diseased vessel either visually or by Quantitative Coronary Angiography (QCA). Such assessment provides the clinician with an anatomical overview of the stenosis segment and parent vessel, including the area reduction, lesion length, and minimal lumen diameter, but does not provide a functional assessment of the effect of the lesion on blood flow through the vessel.
The instantaneous wave-Free Ratio (iFR) has been proposed as an index for classifying coronary artery stenoses into hemodynamically significant and non-significant lesions. Measuring iFR typically requires invasive pressure measurements performed both proximal and distal to a stenosis acquired at a rest state of the patient by inserting a coronary pressure wire into the stenosed vessel. The iFR is then calculated as the average pressure distal to a stenosis during the diastolic wave-free period divided by the average aortic pressure during the wave-free period. However, invasive pressure measurements acquired using a pressure involve risks associated with the intervention necessary to insert the pressure wire into the stenosed vessel, and, for a very narrow stenosis, the pressure wire may induce an additional pressure drop.